Distillation of tar, etc.



June 6, 1933. F. OSBORNE 1,912,393

DISTILLATION OF TAR, ETC

Filed Fb'. 26, 192'! 2 Sheets-Sheet l COKE OVEN BATTERY CON DEN 5 ERCONDENSER JMM BY PMMMW ATTORNEYS June 6, RNE I DISTILLATION OF TAR, ETC

Filed Feb. 26, 1927 2 Sheets-Sheet 2 Fig: cl

Li-IL 1m 3 E 5 l r l 24 COKE OVEN CONDENSER. J

g INVENTOR com; ovgu M%MM ATTORNEYS Patented June 6, 1933 UNITED STATESPATENT OFFICE,

' FRED OSBOKNE, F BI IIRMINGHAM, ALABAMA, ASSIGNOR TO THE BARRETTCOMPANY,

OF NEW YORK N. "1., A CORPORATION OF NEW JERSEY DISTILLATION OF TAR,ETC.

Application filed February 26, 1927.

'This invention relates to improvements in the distillation of tar andthe production I particularly, the invention relates to improvements 1nthe distillation of coal tar and the production of pitches at coaldistillation plants, such as by-product coke oven, gas oven orgas'retort plants.

In the ordinary operation of by-product coke ovens the gases produced bythe coking operation pass from the individual ovens through individualuptake pipes and goosenecks to a collector main or mains common to abattery of ovens. The coke oven gases leaving the ovens at a hightemperature are cooled to separate tar constituents therefrom, the tarconstituents being separated partly in the collector mains and partly insubsequent condensers.

Coal tar produced at by-product coke ovens is commonly shipped orconveyed to tar distillation plants where it is subjected todistillation for the recovery of coal tar distillates and the productionof pitches as residues of the distillation.

The present invention provides an im proved process of and apparatus fordistillation of tar for the production of pitch at a coke oven plant,and with recovery of the volatile oils from the distillation along withthe lighter tars and oils from the coke oven plant. More particularly,the invention relates to improvements in the distillation of tar withhot coke oven gases in modified uptake pipes located between the cokeoven and the collector main.

When tar is distilled by atomizing or spraying it into the hot coke ovengases as they pass through the uptake pipes on their way from the cokeovens to the collector main, the volatile oils driven off from the tarpass with the gases into the collector main, while the pitch or residuefrom the distillation of the tar can be collected and separatelytillation. If the distillation of the tar is carried to the point whereheavy pitch is produced, a correspondingly increased recovered as aproduct of the disv Serial No. 171,154.

amount of heavy oils are driven off from the tar during the distillationand pass over with the gases into the collector main. These heavy oilstend to separate out with the tar in the collector main, and if theresulting tar is returned for further distillation to produce pitchtherefrom, the heavy oils are again distilled and returned to thecollector main and tend to increase in amount as they are repeatedlydistilled by the hot coke oven gases and condensed in the collectormain,

The improved method of operation of the present invention enables thisobjection to be overcome, and enables the oils or distillates driven offduring the distillation of tar to be recovered in the ordinaryby-product recovery system of the coke oven plant without theaccumulation of heavy products of the distillation in the tar to beredistilled.

The present invention relates particularly to operations in which tarcontaining high According to the present invention, I pro- I videseparate collecting means, such as a separate collector main, for themodified uptake pipes which are employed for the distillation of tar, sothat the distillates from such distillation do not enter the ordinarycollector main, but are kept separate in the separate collector main;and I pass the gases and vapors from such separate main to thecondensing system connected with the ordinary cross-over inain of thebattery. In this way, I keep separate the heavy oils distilled from thetar, and recover them separately either in the separate collector main,or pass them over to the condensers of the battery and condense andrecover them in admixture with the lighter tar and oils from the normaloperation of the battery.

From the standpoint of apparatus or equipment, I provide, in addition tothe ordinary collector main and condensing system of the battery, aseparate short collector main or mains and I connect the uptake pipeswhich are modified to permit tar distillation therein, with the separateshort collector main so that the gases and vapors resulting from thedistillation are collected therein; and I then pass the gases and vaporsfrom the separate main to the direct or indirect coolers forming part ofthe main condensing system of the battery. The modified uptake pipes arealso advantageously connected with the usual collector main, andprovided with valves for enabling the gases from the uptake pipes to bedischarged either into the ordinary main, when not employed fordistillation, or into the separate collector main, when employed forsuch distillation.

The distillation of the tar, in the modified uptake pipes, is effectedby the heat contained in the hot coke oven gases passing upwardlytherethrough, for example, by atomizing or spraying the tar or otherwisebringing it into intimate contact with the hot coke oven gasesimmediately after they leave the coke ovens, or at least while they areat a temperature high enough to accomplish the desired distillation.This distillation of the tar by the hot coke oven gases gives pitch or aheavy residue, and increases the vapor content of the gases by theVapors driven off from the tar during the distilla-r tion. Some of theheavier constituents of the gas are removed therefrom by the scrubbingaction of the tar spray and are added to the pitch residue, while theremainder of the condensable constituents of the hot coke oven gasespass with the added vapors from the distillation to the separatecollector main.

The number of ovens provided with the modified uptake pipes and employedfor the distillation of tar, can be varied. A few only of these modifieduptake pipes are suffi- .cient for distilling the tar from an entirebattery. However, by providing connections between the modified uptakepipes and the ordinary collector main, as well as with the separatecollector main, it is possible to provide a considerable number of themodified uptake pipes and to use as many or as few of them as desiredfor tar distillation. Those which are not so employed can be opened tothe ordinary collector main, while those which are employed for tardistillation can be opened to the separate collector main.

The separate collector main, which collects the gases and vapors fromthe distillation, may be provided with tar or ammonia liquor spray toassist in condensing the heavier constituents, and the tar or oil thuscondensed can be drawn oil from the separate collector main as one ofthe products of the process. The gases and vapors that remain after suchpreliminary condensation are then passed over to the ordinary coolers orcondensers to which the gases and vapors from the ordinary collectormain pass for the recovery of light tars and oils therefrom. In thisway, a separate condensing system is not necessary, while the. heavieroils from the distillation of the tar are prevented from entering theordinary collector main and becoming admixed with the heavy tarseparated therein.

From the standpoint of battery operation, the greater part of thebattery may be operated in the ordinary way with discharge of the gasesfrom the ovens into the common collector main which may be provided withtar and ammonia liquor sprays, and in which the heavier tar will bethrown down and separated as a heavy tar product. The remaining gasesand vapors then pass over through the cross-over main to the coolers orcondensers which may be of the direct or indirect type and in which thegases are further cooled to separate the greater part of the remainingcondensable constituents therefrom.

That part of the battery which is provided with the modified uptake pipeleading to a separate collector main, is operated with tar sprays toeffect distillation of the tar by the hot coke oven gases in themodified uptake pipes and the resulting admixed gases and vapors thenpass to the separate collector main where some of the heavierconstituents may be condensed and separated, and the remaining gaseousand vapor mixture then passes to the condensers or coolers abovementioned.

The tar which is distilled according to the present process, may be tarproduced at the same coal carbonizing plant at which it is distilled, orit may be tar from another coal carbonizing or other plant. It may be aheavy tar, a light tar, or tar of widely varying properties. It may be aheavy tar containing only part of the oils from the coal distillation,or it may contain all or practically all of the condensable oils, aswhere all of the tar constituents are normally collected or condensedtogether. The manner in which the tar is brought into direct contactwith the hot vapors can be varied. A suitable atomizing or spray nozzle,to which the preheated and thinly fluid tar is supplied under asufiicient pressure to bring about atomizing or spraying and resultingintimate contact of the tar with the hot gases, can be located in theupper part of the modified uptake pipe to bring the tar into intimatecontact with the hot gases.

A single tar spray can be used in each of the individual uptake pipes,or a plurality or series of such sprays, and the rate at which the taris sprayed, as well as its temperature, can be regulated and controlledto obtain a greater or less degree of distillation of the tar andtheproduction of distillates of desired characteristics and of harder orsofter pitches or pitch-like products.

The gases esca ing from the top of a coke oven are at a hi temperature,e. g., around 600 to 700 or in some cases much hi her. The temperatureof these gases is su ciently high so that effective distillation of thetar can be accomplished by an intimate and regulated spray of the tarinto the hot gases. By employing the gases at practically top-of-oventemperature their maximum heating and distilling effect is utilized. Theamount of tar and the intimacy and time of contact of theparticles ofthe tar spray with the gases, and the nature and amount of oil distilledtherefrom, can be varied. I

By regulation of the rate and type of tar spray and its temperature ofpreheating, and by redistillation when necessary, it is possible toregulate the hardness of the pitches produced, and produce softer orharder pitches, as desired, and oils of different characteristics may beformed. The further distillation of the pitch first produced to recoveradditional oil therefrom, can be carried out in the same uptake pipestill, or it may be subjected to further dis-' tillation in anotheruptake pipe still. The invention is particularly advantageous in thatthe distillation of the tar or pitch effects the vaporization of some ofthe heavier oils which would normally be thrown down in the ordinarycollector main as a part of the heavy tar andwhich, if so thrown down,would be returned and redistilled repeatedly with resulting accumulationof the amount of these heavy oils in the heavy tar. By separatelycollecting these heavy oil vapors in the separate collector main, theycan then be passed over to the ordinary condensing system and kept outof the heavy tar. The invention thus provides a means for distilling theheavy tar and separating heavy oils therefrom and recovering these heavyoils in the ordinary condensing system of the coke. oven plant.

The invention will be further illustrated by the following more detaileddescription taken together with the accompanying drawings, which showapparatus embodying the invention and adapted for the practice of theprocess of the invention, but it is intended and will be understood thatthe invention is illustrated thereby but not limited thereto. I

In the accompanying drawings,

Fig. 1 shows a plan view of art of a coke oven battery modified to emb ythe present invention and to permit operation of. the process of theinvention,

Fig. 2, is a view in elevation showing part of one end of the battery,

Fig. 3 is an enlarged sectional view through the modified uptake pipesand collector main, and,

' Fig. 4 shows one form of modified uptake ipes.

p The invention is of more or less general application to differenttypes and construction of by-product coke ovens such as Semet-Solvayovens, Koppers ovens, etc., but will be more particularly described andillustrated in connection with by-product coke ovens of the Semet-Solvaytype.

In the drawings, the coke oven is illustrated conventionally at 1 andhas the usual gas outlet 2 for the escape of the hot coke oven gases.The outlet pipe 3 is seated in a suitable seal over the gas outlet 2 andcon.- nects at its upper end with the lower end of the casing 4. Theupper end of the casing 4 connects with the uptake L 5 which leads tothe ordinary collector main 6 and to the separate collector main 7,valves 8 and 9 being provided for connecting the uptake L with one orthe other of these mains as desired.

The casing 4 is enlarged to provide a space around the inner pipe member10 which extends upwardly into the enlarged casing 4. The lower ends ofthe pipe 10 and the casing 4 are preferably integral or otherwisearranged to provide an annular receptacle for the collection of thepitch or residue from the distillation.

Located within the casing 4 and above the end of the pipe 10 is a baflieor hood 11 and above this is a spray head 12 connected with a pipe 13for spraying tar to be distilled.

An outlet 14 for pitch or residue is located.

at the bottom of the enlarged casing 4 for discharging the pitchor--residue from the annular space at the bottom of the casing, to atank or other receptacle 14'. The casing 4 is attached at its lower endto the outlet pipe 3 which in turn is sealed in the roof structure ofthe ovens.

.the casing.

The connection from the uptake pipe stills to the collector mains may beprovided with a spray 19 for cooling or assisting in cooling condensableconstituents of the gas and for spraying the valves 8 and 9. Ad ditionalspray nozzles 20 may also be provided in the ordinary collector main 6and other sprays 21 in a separate collector main 7. Ammonia liquor canbe used in such sprays, or tar, or a mixture of liquor and tar.

The coke oven battery illustrated in Fig. 1 has the ordinary pipes 22connected with the usual collector main 6. The usual crossover mainisindicated at 23, leading to the coolers or condensers 24 and 25connected to decanter 26. The exhauster for drawing the gases throughthe system is indicated at 27. This part of the system comprising theuptake pipes 22, collector main 6, cross-over main 23, coolers, etc., isthe ordinary byproduct coke oven system.

The tar collected in the collector main and cross-over main is shown asrunning to a tar collecting tank 28 in which the tar separates from theammonia liquor and this tar in turn is shown as leading to a dehydrator29 for completely freeing the tar from water or preheating it fordistillation. The dehydrator may be of any suitable construction. Thedehydrated and preheated tar is then pumped by the pump 30 through thetar supply line 13 to the spray nozzles 12. Undehydrated tar may be usedif desired. It is, however, advantageous to the spraying operation thatthe tar be preheated to the extent that it is in a thinly fluidcondition as it is delivered to the sprays.

The separate collector main has a discharge pipe 33 leading to adecanter 34 for collecting the heavy condensates separated in thisseparate collector main. The uncondensed vapors and admixed gases passfrom this separate collector main through a separate cross-over main 32to the condensers or coolers 24 or 25 above described. The pipingarrangement is such that the gases and vapors from the separatecollector main may pass either to the condenser or cooler 24 or to thecondenser or cooler 25 or through the two condensers or coolers inseries, so that the products separated out from the gases and vapors maybe admixed with one or the other of the products from these separatecondensers or coolers, where these products are kept separate. A pipe 35controlled by a valve 36 permits delivery of gases and vapors from thepipe 32 directly to the cross-over main 23 when such operation isdesired.

The products thus separated and recovered in the condensers and coolers24 and 25 will be composite products, being made up in part fromproducts condensed from the main coke oven gases of the battery and inpart from the distillates from the separate distilling system. Therelative proportions of these separate condensed constituents can beregulated by regulating the extent to which the admixed gases and vaporsare cooled and scrubbed in the separate collector main, and byregulating the condenser or cooler into which the separate .of theuptake stills will gases and vapors pass for further condensation. Afurther regulation is possible by increasing or decreasing the amount oftar distilled, or the extent to which the tar is distilled. When theamount of tar to be distilled is increased, a larger number of theuptake pipe stills can be employed for the istillation and connectedwith the separate collector main. When the amount of tar to be distilledis decreased, a smaller number he required. In the apparatusillustrated, a greater or smaller number of the u take pipes can beemployed for the distil ation and connected to the separate collectormain, while those which are not so employed can be connected with theordinary collector main, thus keeping separate the gases employed forthe distillation from those which are not so employed.

Considering the operation of a single coke oven battery, the inventionmakes possible the distilling of all of the heavy tar collected in thecollector and cross-over mains and the driving off and recoverytherefrom of volatile oils and the production of pitch, the volatileoils being carried over and collected in the ordinary condensing systemof the battery. In this way, all of the heavy tar is converted intopitch and distillate oils, and all of the distillate oils are separatelyrecovered along with the lighter tars and oils from the normal operationof the battery.

While I have described and illustrated a particular type andconstruction of uptake pipe still, and a particular arrangement and sizeof separate collector mains, and a particular arrangement of connectionswith the ordinary condensing system, it will be evident that theinvention in its. broader aspects can be carried out in the apparatus.of

other constructions and that variations and modifications can be madetherein without departing from the spirit and scope of the invention.

I claim:

1. The improvement in the operation of the by-product recovery system ofa coal distillation .plant which comprises collecting coal distillationgases from part of a battery and removing heavier tar constituentstherefrom, distilling tar by bringing it into contact with hot coaldistillation gases evolved from another part of the battery to distillvolatile oils from the tar and produce pitch therefrom, collecting theresulting gases and vapors separately from the gases from the mixturewith condensates from the li hter constituents of the gases firstmentione 2. The improvement in the operation of the by-product recoverysystem of a coke oven plant which comprises collecting coke oven gasesfrom part of a coke oven battery and recovering heavier tar constituentstherefrom, distilling coal tar to pitch by bringing it into contact withhot coke oven gases evolved from another part of the battery to distillvolatile oils from the tar and produce a gas mixture containing vaporsof heavier condensable constituents and lighter condensable constituentsdistilled from the tar, recovering the heavier condensable constituentsfrom said gas mixture apart from the aforementioned recovery of heaviertar constituents from coke oven gases, and recovering lighterconstituents from said gas mixture together with lighter constituentsfrom the first mentioned coke oven gases by combining the gases with thegas mixture, and cooling the combined gases.

3. The improvement in the operation of the by-product recovery system ofa coke oven plant, which comprises cooling coke oven gases from part ofa coke oven battery to separate heavier tar constituents therefrom,recovering the heavier tar constituents and distilling them by bringingthem into contact with hot coke oven gases evolved from another part ofthe battery thereby distilling the tar to ,pitch and forming'a gasmixture containing volatile oils distilled from the tar, separatelycollecting the resulting gas mixture and combining it with said cokeoven gases from which heavier tar constituents have been separated, andcooling the combined gases to separate condensable oils therefrom.

4. The improvement in the operation of the by-product recovery system ofa coal distillation plant, which comprises collecting coal distillationgases from part of a battery and removing heavier tar constituentstherefrom, distilling tar by bringing it into contact with hot coaldistillation gases evolved from another part of the battery to distillvolatile oils from the tar, cooling these gases to remove heaviercondensable constituents, blending these gases with the first-namedgases after said removal of heavier tar constituents and cooling theblended gases to recover lighter condensable constituents.

In testimony whereof I afiix my signature.

FRED OSBORNE.

